1. Field of the Invention
The present invention relates to data storage devices, storage media controllers and storage media control methods.
2. Description of the Related Art
For a storage media with a high data rate, such as a DDR SDRAM abbreviated from Double Data Rate Synchronous Dynamic Random Access Memory, a data strobe signal (e.g. a DQS signal for a DDR) is generally taken into account in the read/write operations of the storage media as well as a clock signal (e.g. a CK signal for a DDR) and a data signal (e.g. a DQ signal for a DDR). The CK signal may be transmitted via a differential pair CK and CK#. The DQS signal may be transmitted via a differential pair DQS and DQS#.
FIG. 1 shows signal waveforms for a write operation of a storage media, including a clock signal CK, a data strobe signal DQS and a data signal DQ. The clock signal CK and the data strobe signal DQS are synchronously triggered at time point Ts and accordingly data is retrieved from the data signal DQ and written into the storage media.
However, when the data rate is increased, a trace length difference on the motherboard between the clock signal CK and the data strobe signal DQS may considerably affect the synchronization between the clock signal CK and the data strobe signal DQS. Especially, when the trigger points observed from the clock signal CK and the data strobe signal DQS are not synchronous to each other, the clock signal CK and the data strobe signal DQS may be received by the storage media asynchronously and thereby the write operations fail.